Besides being one of the most standard approximations for pi (divided by 100), 314^2 + 1 is prime. [Patterson]

The smallest pisemiprime: a semiprime formed by the initial
digits of the decimal expansion of pi. The sequence begins
314, 314159265358, 314159265358979323,
3141592653589793238462643383279502, 3141592653589793238462643383279502884197, .... [Najafi]